[kubernetes] Fix Quantity.hashCode to honor equals/hashCode contract

Quantity.equals compares the underlying BigDecimal by value
(ObjectUtils.compare -> BigDecimal.compareTo, scale-insensitive), but
hashCode used Objects.hash(number) which is scale-sensitive. Value-equal
quantities such as "1" and "1000m" (1.000) are therefore equal yet
produce different hash codes, breaking HashMap/HashSet lookups.

Normalize the scale with BigDecimal.stripTrailingZeros() before hashing
so the hash is consistent with the value-based equals.

Adds a focused unit test (fails before, passes after).

Author: yue9944882

kubernetes/src/main/java/io/kubernetes/client/custom/Quantity.java

@@ -90,7 +90,10 @@ public boolean equals(Object o) {
 
   @Override
   public int hashCode() {
-    return Objects.hash(number);
+    // equals() compares numbers by value (scale-insensitive via BigDecimal.compareTo), so the
+    // hash must also be scale-insensitive to honor the equals/hashCode contract. Normalize the
+    // scale before hashing; otherwise e.g. "1" and "1000m" are equal but hash differently.
+    return Objects.hash(number == null ? null : number.stripTrailingZeros());
   }
 
   public static class QuantityAdapter extends TypeAdapter<Quantity> {

kubernetes/src/test/java/io/kubernetes/client/custom/QuantityTest.java

@@ -30,4 +30,17 @@ void containsInSet() {
 
     assertEquals(set1, set2, "Sets of equal elements are not equal");
   }
+
+  @Test
+  void equalQuantitiesWithDifferentScaleHaveEqualHashCode() {
+    // "1" parses to scale 0; "1000m" parses to 1000 * 10^-3 = 1.000 (scale 3). They are equal by
+    // value, so the equals/hashCode contract requires equal hash codes (and HashSet membership).
+    final Quantity a = Quantity.fromString("1");
+    final Quantity b = Quantity.fromString("1000m");
+
+    assertEquals(a, b, "quantities with the same value should be equal");
+    assertEquals(
+        a.hashCode(), b.hashCode(), "equal quantities must have equal hash codes (equals/hashCode contract)");
+    assertEquals(Set.of(a), Set.of(b), "equal quantities must be interchangeable as hash-set members");
+  }
 }